The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Engine systems include an engine having an air intake manifold. Air flows into the intake manifold through an inlet. An air filter removes dirt or debris from the inlet air. A throttle valve regulates the air flow into the intake manifold. A controller determines an appropriate air/fuel (A/F) ratio for engine operation based on the air flow and other engine parameters.
Internal combustion engines having one or more cylinders may be provided with at least one pivotable member, such as a wave-transfer shutoff valve. The pivotable member opens and closes an acoustic through-bore or other acoustic wave communication passages between otherwise differentiated portions of the intake manifold of the engine. The pivotable member enables the intake manifold to be adjusted to at least two discrete acoustic resonance geometry configurations.
In one case, the inlet manifold has two intake manifold portions. A block or flapper valve adjusts the acoustic passage between the portions to either an opened position or a closed position. When the valve is in the closed position, the two portions of the intake manifold are in acoustical wave communication. When the valve is in the opened position, the fluid materials in the two portions are separated from acoustical wave communication. The intake manifold is therefore adjustable to two different acoustic resonance geometry configurations. A degree of freedom is thereby provided to handle certain aspects of the fluid flow within the intake manifold.
Typically a position sensor is mounted to the valve to indicate to the controller an actual position of the valve. The actual position is used by control systems to diagnose a malfunction of the valve. For example, the actual position and a commanded position may be compared to detect the malfunction. However, an indication of the position of the valve may not be sufficient to indicate the true status of the valve. Additional methods should be employed to ensure the valve is functioning during vehicle operation according to design requirements.